Chocolate Chip Cupcakes with Chocolate Chip Frosting

Makes 30
3 1/4 cups sifted cake flour (not self-rising)
1 1/2 tablespoons baking powder
1/4 teaspoon salt
7 ounces (1 3/4 sticks) unsalted butter, softened
1 3/4 cups sugar
1 cup plus 2 tablespoons milk
1 tablespoon pure vanilla extract
5 large egg whites, room temperature
2 cups semisweet chocolate chips
Chocolate Chip Frosting
Directions
Make cupcakes as directed in Basic Cupcake How-To, omitting eggs and using milk and vanilla for wet ingredients. Beat egg whites to stiff peaks, and fold into batter. Fold in chocolate chips. Bake cupcakes about 22 minutes. Frost with buttercream, and serve immediately